The present invention relates to a total flow turbine which utilizes expanded hot water to generate power.
The present inventor has proposed a total flow turbine in which hot water is partially expanded and accelerated in a nozzle (Japanese patent application No. 195377).
In such a total flow turbine, when the pressure differential or pressure ratio which represents the difference between the pressure of the hot water before it reaches the nozzle and the pressure thereof after it has passed through the nozzle is small, the two-phase flow of hot water and steam suffers from the following problems at the outlet of the nozzle.
(1) Flushing (evaporation) of hot water is delayed within the nozzle.
(2) The size of water droplets in the nozzle has a wide scatter band. As a result, the flow speed of water droplets in the nozzle also has a wide scatter band.
(3) Water droplets are not easily made fine.
The lower the pressure of the hot water, the more such tendencies prevail. As the flow of hot water becomes uneven at the outlet of the nozzle, i.e., as the size and flow speed of water droplets vary, the flow speed and flow angle of water droplets relative to the inlet of the moving blade also vary greatly, causing the water droplets to collide with the leading edge of the moving blade and thereby result in additional loss.